This document applies to the basic safety and essential performance of a ventilator in combination with its accessories, hereafter referred to as ME equipment: -- intended for use in an environment that provides specialized care for patients whose conditions can be life-threatening and who can require comprehensive care and constant monitoring in a professional healthcare facility; NOTE 2 – For the purposes of this document, such an environment is referred to as a critical care environment. Ventilators for this environment are considered life-sustaining. NOTE 3 – For the purposes of this document, such a ventilator can provide ventilation during transport within a professional healthcare facility (i.e. be a transit-operable ventilator). NOTE 4 – A critical care ventilator intended for use in transport within a professional healthcare facility is not considered as an emergency medical services environment ventilator. -- intended to be operated by a healthcare professional operator; and -- intended for those patients who need differing levels of support from artificial ventilation including for ventilator-dependent patients.